The effect of varying low-dose protocols on perceived image quality in multidetector CT in a rabbit model of acute appendicitis.

The aim of this study was to evaluate the value of multidetector CT (MD-CT) with low-dose protocols in the diagnosis of acute appendicitis in a rabbit model. Ten New Zealand white rabbits underwent ligation of the appendix. MD-CT (Siemens Somatom Plus 4 Volume Zoom) was performed using three low-dose protocols: 80 kV/70 mAs; 80 kV/50 mAs; and 80 kV/20 mAs. Axial and coronal reformations were performed. Three experienced radiologists evaluated the images using a four-grade score: (1) excellent; (2) good; (3) moderate; and (4) not sufficient. Diagnosis was confirmed histopathologically. The overall score for the 80 kV/70 mAs was 1, for the 80 kV/50 mAs protocol 1.3, and the 80 kV/20 mAs protocol reached an overall score of 2. The coronal reformations reached with 1.1 (80 kV/70 mAs), 1.2 (80 kV/50 mAs), and 1.4 (80 kV/20 mAs) had a slightly better median score than the axial reconstructions. In cases of inconclusive ultrasound and clinical presentation, the use of MD-CT can be considered when evaluating children for suspected appendicitis.